| Packaging Film of PP/LDPE/PLA/Clay Composite: Physical, Barrier and Degradable Properties | |
| Mooninta S., Poompradub S., Prasassarakich P. | |
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| This work sought to improve the properties of polypropylene (PP) for single layer film application by incorporating low density polyethylene (LDPE), poly(lactic acid) (PLA) and montmorillonite (MMT). The addition of LDPE in PP improved the elongation at break and tear strength. The PP/LDPE blend at a 80:20 (w/w) ratio was selected for blending with PLA and MMT and the PP/LDPE/PLA/MMT composite showed an increased tensile modulus, while the elongation at break decreased, with increasing PLA and MMT contents. The morphological structure of the respective nanocomposites was examined using X-ray diffraction, transmission electron microscopy and scanning electron microscopy analyses. For the barrier properties, the incorporation of PLA and MMT in PP/LDPE blend tended to dramatically decrease the oxygen permeability but slightly increase the water vapor permeability. Moreover, the PP/LDPE/PLA/MMT composite as a new effective film decreased the tomato loss weight during low temperature storage (15–20 °C) compared to the PP film. © 2020, Springer Science+Business Media, LLC, part of Springer Nature. | |
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| Blending; High resolution transmission electron microscopy; Plastic films; Polypropylenes; Temperature; Elongation at break; Low density polyethylene(LDPE); Low-temperature storage; Montmorillonite (MMT); Morphological structures; Oxygen permeability; Scanning electrons; Water vapor permeability; Scanning electron microscopy; composite; film; montmorillonite; particulate matter; physical property; polymer; reinforcement; Lycopersicon esculentum | |
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| Cryogen-free comprehensive heartcut multidimensional gas chromatography using a Deans switch for improved analysis of petrochemical products derived from palmitic acid oxidation | |
| Thongdorn-Ae N., Nhujak T., Janta P., Rueangthaweep A., Hinchiranan N., Kulsing C. | |
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| Comprehensive heartcut multidimensional gas chromatography was applied with example application for analysis of a sample obtained from palmitic acid oxidation in a Rancimat instrument. The system utilized a single Deans switch (DS) located between first dimensional semi-standard nonpolar (30 m) and second dimensional polar (60 m) columns. A cyclic multiple heartcut strategy consisting of 150 heartcuts with a 0.2 min window was applied offering comprehensive analysis and injection of a narrow band of compounds onto the second column without use of cryogenic trapping devices. Untargeted compound analysis of the sample prepared by solid phase micro-extraction was performed based on match between the experimental MS spectra and first dimensional retention indices with that from the NIST library. The sample contained the major compounds of 2-octanone, 1-methylcyclohexanol, 2,3,6-trimethylphenol, 3-phenylpropanol and 2-nonanone. This approach was then evaluated based on peak capacity and the number of identified compounds. Compared with one dimensional gas chromatography providing a total peak capacity of 172 and 43 identified compounds, the analysis performance was much more improved with a capacity of 5840 and 235 identified compounds by using comprehensive heartcut multidimensional gas chromatography with the total analysis time of 15.3 h. By comparison within the same set of identified compounds, the one dimensional and multidimensional approaches provided the MS match scores of 769 ± 81 and 836 ± 88, respectively. In addition, the nonlinear relationship between the analysis time and number of identifiable peaks was calculated according to the set of 235 compounds. This revealed that the analysis time could be shortened with the compensation of lower separation performance, where application of a 2.5 min heartcut window with the total analysis time of 1.2 h could result in the total peak capacity of 390 with 150 identifiable compounds. This journal is © The Royal Society of Chemistry. | |
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| Palmitic acid; Petrochemicals; Saturated fatty acids; 2 ,3 ,6-Trimethylphenol; Comprehensive analysis; Multi-dimensional approach; Multidimensional gas chromatography; Non-linear relationships; Petrochemical products; Separation performance; Solid phase micro extraction; Gas chromatography | |
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| Bacterial cellulose membrane conjugated with plant-derived osteopontin: Preparation and its potential for bone tissue regeneration | |
| Klinthoopthamrong N., Chaikiawkeaw D., Phoolcharoen W., Rattanapisit K., Kaewpungsup P., Pavasant P., Hoven V.P. | |
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| Bacterial cellulose membrane (BCM) has been recently recognized as a new generation of carbohydrate-based nanomaterial that possesses a great potential in tissue engineering applications. This research aims to develop an active non-resorbable guided tissue regeneration (GTR) membrane from BCM by conjugating with plant-derived recombinant human osteopontin (p-rhOPN), an economically produced and RGD-containing biomolecule. The BCM was initially grafted with poly(acrylic acid) (PAA) brushes to form poly(acrylic acid)-grafted BCM. Multiple carboxyl groups introduced to the BCM by PAA can serve as active anchoring points for p-rhOPN conjugation and yielded p-rhOPN-BCM. All chemically modified BCMs were characterized by attenuated total reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy, while their surface morphology was evaluated by field emission-scanning electron microscopy and atomic force microscopy analyses. The amount of p-rhOPN adhered on the membrane was quantified by enzyme-linked immunosorbent assay. The immunocytochemistry, two-stage quantitative real-time reverse transcriptase polymerase chain reaction and in vitro mineralization analyses strongly suggested that p-rhOPN-BCM could elicit biological functions leading to the enhancement of osteogenic differentiation of human periodontal ligament stem cells as effective as BCM conjugated with commercially available rhOPN from mammalian cells (rhOPN-BCM), suggesting its potential to be used as GTR membrane to promote bone tissue regeneration. © 2020 Elsevier B.V. | |
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| carboxyl group; nanomaterial; osteopontin; polyacrylic acid; cellulose; osteopontin; recombinant protein; SPP1 protein, human; affinity chromatography; Article; atomic force microscopy; bacterial cellulose membrane; bacterial membrane; bone defect; bone mineralization; bone tissue; cell differentiation; controlled study; enzyme linked immunosorbent assay; field emission; Fourier transform infrared spectroscopy; immunocytochemistry; immunofluorescence; in vitro study; mammal cell; MTT assay; nonhuman; ossification; osteoblast; periodontal ligament; quantitative analysis; real time reverse transcription polymerase chain reaction; scanning electron microscopy; stem cell; tissue engineering; tissue regeneration; X ray photoemission spectroscopy; artificial membrane; bacterium; bone regeneration; chemistry; cytology; human; metabolism; Bacteria; Bone Regeneration; Cellulose; Humans; Membranes, Artificial; Osteopontin; Periodontal Ligament; Recombinant Proteins; Stem Cells | |
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| Highly Soluble Indigo Derivatives as Practical Diesel Absorption Markers | |
| Modsiri S., Pongmaneerat P., Tawil S., Promarak V., Thamyongkit P. | |
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| This work describes the practical production of novel indigo derivatives from commercially available and economically friendly indigo and investigation for their potential use as diesel markers. Introduction of solubilizing long alkyl chains into an indigo molecule via formation of arylimino moieties at its carbonyl sites and amidation at its amino groups greatly enhances the solubility in diesel and several common organic solvents. Effects of the number and position of the alkyl chains on the absorption behavior of the compounds are discussed. Because of their superior absorption in a region where the diesel cannot absorb, indigo N-arylimine and N-monoacyl-substituted indigo derivatives can serve as diesel absorption markers at detection wavelengths of 590 and 575 nm, respectively. UV-visible spectrophotometric analysis suggested that this target marker is stable in diesel for at least 3 months under ambient conditions. Furthermore, physical testing according to the American Society for Testing and Materials standards indicates that addition of these markers at a concentration of 5 ppm does not significantly affect the physical properties of the original diesel, thus confirming the applicability of these compounds for marking of commercial diesels. Copyright © 2020 American Chemical Society. | |
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